Long after midnight, I came to Jerez on the road from Cádiz, with blizzards of moths rushing towards the lights of the car like crazed supplicants to a shrine. A freakishly wet spring followed by the savage furnace blast of early summer had lured tens of thousands from their journey across the Strait of Gibraltar, until the whole of the southern edge of Spain seemed to vibrate with their sound. The fifth largest city in Andalucía, Jerez is a perfect place to start a tour of the hill towns (pueblos blancos) and nearby beaches of Costa de la Luz, the stretch of spectacular natural reserves running from the mouth of the Guadiana River on the Portuguese-Spanish border down to the small city of Tarifa just over the water from Tangier.

Nights in Jerez are for indulgence. On a wooden carousel in Plaza del Arenal, bright-painted Spanish horses are polished for the hours and children to come, and gas lamps glimmer on tables outside sherry bars along Calle San Pablo. Walk for long minutes through the elegantly shabby old city and you will find nothing but silent alleys and part-derelict houses sprouting fig trees or a weeping bottlebrush. Scarlet pomegranate flowers loll over hoardings decades-thick with posters for bullfights, a powerful flash-vision of western Asia meeting ancient Crete, that quintessentially southern-Spanish union. Pictured: Vejer Old Town.

Moors, Romans, Phoenicians: everywhere is the memory of countless invaders. And then, rounding a neglected corner, you will come upon a smart avenue rammed with people talking in that sociable Andalusian way. An English friend who has lived here for years says he still marvels at the sound of grandmothers deep in conversation outside his door at 3am. What can they possibly be talking about? What new and bewitching thing can have occurred since their last long conversation that afternoon? On a spring evening in the medieval church of San Miguel a wedding is taking place. Glancing through the open doors into the gloomy interior, I can make out pew after pew filled with beautiful women in sequined gowns, gold bracelets flashing on their wrists. The unbelievable glamour of well-to-do Spanish women in early middle age.

Outside on a bench the father of the bride sits smoking in a grey formal suit, cooling himself with a straw fan, surrounded by celebratory friends. None of them is remotely bothered about missing the service. Inside the church or out, so long as the front doors remain open to broadcast the occasional incantation of the priest, it's all the same to the Andalusian, whose attitude to Catholicism is born of a deep familiarity and ease. Pictured: Jerez cathedral; Casa La Siesta hotel.

Twenty miles east of Jerez in the high town of Arcos, two little girls in bloomers play with spinning tops while their younger sister, her hair curled and immaculately parted, attempts to catch a beetle in a cup. It is important to communicate how perfectly antique this scene is, how unlike anything you might see elsewhere in modern Europe. There is an extreme innocence to the children in southern Spain. Mollycoddled, usually dressed to the nines and indulged with buns after their long siestas, they waddle the cobbles until at least 1am while their parents have supper and jabber with neighbours, moving up and down Calle Dean Espinosa in a smoothly milling stream. There is a richness to this ritual. The gathering and eating, the promenading and flirting.

'What time do you shut?' I ask the harried waitress at Taberna Jóvenes Flamencos. 'Until there are no more people!' she hoots. In her arms are plates of chicharrones, cubes of fried, fatty pork belly, intensely salted and served with glasses of ice-cold white sherry. On the wall, the jewelled costume of a once-feted toreador hangs like the flag of a conquering knight. Weeds spring from the roofs of the houses along the incline up to a square dotted with lime trees outside the 15th-century Basilica de Santa Maria, where on feast days a statue of the Virgin luxuriates on a bower of white hyacinths.

During an evening of flamenco in the square the town sits watching a young woman dance a kind of malagueña, but one of particularly savage fury. Her hair wild, she finally falls into a swoon as though completely exhausted from all the suffering and squalor of a love so lost she belonged to nobody and nowhere. 'Pero yo ya no soy yo, ni mi casa es ya mi casa,' wrote the great Andalusian poet Lorca. ('But now I am no longer I, nor is my house any longer my house.') Moments later, she stands up with a grin, her rage-trance forgotten, and everyone cheers and troops down the hill to the bars for more food.

To eat in southern Spain is really to snack between snacks. One place might sell small plates of delicious grilled aubergine and goat's cheese drizzled with honey, another might specialise in taquitos de pescado en adobo, melting fried morsels of white fish that tell you the sea, and miles and miles of unspoilt dunes, is close at hand. Even the olives here taste subtly of anchovies.

Cross the fertile plains of the coastal barbate river in August and you will pass molten fields of sunflowers and wheat. Combine harvesters cling to little hills tilted towards the sun. Massive cabbage whites bash against my car as I idle along empty roads bordered by in-leaning crape myrtle and overlooked by storks in disordered nests on the top of telegraph poles. Vultures circle fields of black horned cattle. The city of Medina is steep. So steep that to get to the top requires passing through an old Moorish gate in the middle of town and then what feels like falling to your knees and crawling vertically into the ancient quarter. Medina is the oldest city in Europe. Cádiz may officially claim that title but, in fact, tiny Medina was the centre of a Phoenician colony first and then a major centre under Roman occupation. A grand Visigoth fortress became a Christian castle, in whose windswept remains tiny stonechats are now blown about like blossom among enormous blood poppies. It can feel hotter here at 5pm than it does at midday despite the constant breeze, hot and ruminative and melancholy. There is nobody on the surrounding streets, nobody in Plaza de la Iglesia Mayor, nobody in Santa María la Coronada Church at the tip-top of the town. Inside, the statue of a tortured Saint Sebastian is covered in dust. A bench for a 15th-century inquisitor sits a few feet from a stone gargoyle, his tongue protruding down.

After the noise and gossip of Arcos, the sound of just wind and crested larks and the view across the plains, unchanged for more than a thousand years save for the occasional white forest of wind turbines, make Medina feel gorgeously lost. In the only bar up this high a family plays cards and decimates a plate of cherries and sheep's-milk cheese. Medina is deeply traditional: work from 7am until 2pm in summer then a siesta ending at 5.30pm, followed by cake and sugared milk indoors, and perhaps a visit to the sweltering beach. The locals will dutifully change into winter clothes on 1 October even if it is still 28˚C. 'Cristo todopoderoso, it's damn hot,' they'll complain, shifting uncomfortably in their woollen jackets, waiting for the cooler weather that might not come for weeks. If Andalucía teaches you one thing, it's patience.

And what of these famous, untainted beaches? Bright with an implacable light, the Costa de la Luz is so capricious it will never find favour with those seeking the drugging reliability of the Costa del Sol. The Atlantic winds sweep in with an immense power, wrapping your cheeks around the back of your head, winds you can actually lean into on the beach at Roches and El Palmar but which can whip up suddenly to sandblast bathers, forcing families to run shrieking in towels to the safety of the juniper forests hugging the coastline. On other days all is calm. On a cloud-scudding afternoon at the Bolonia Beach Café, a white-sanded beauty spot overlooked by the yellow remains of a Roman city, I drink vinegary gazpacho and work my way through a dish of fried anchovies. The boquerones here are sometimes as small as whitebait, sometimes as startlingly large as sardines. Plates of bones and spines pile high in the open back kitchen and, in the shrubland beyond, horses and donkeys stand perfectly still, their gaze drawn helplessly towards Africa just over the water.

In the town of Tarifa, as far south as you can get in Spain, small groups of teenagers stagger from ferries clutching fake-silver teapots bought in the souks of Tangier, 30 minutes away. Tarifa is where Andalucía's teenagers come to kitesurf and party, camping under the mulberry trees beyond the dunes. Along the little stretch of sand outside the Hotel Arte y Vida dogs mingle happily with all human life: nose rings and G-strings, Spiderman trunks and ping-pong matches. Oh, the girls. The limbs. Everywhere slim legs and bracelet- jangling arms. Grandmothers pose proudly for photographs with granddaughters dressed in outrageously short Daisy Dukes, hooped earrings glinting in the dark curls they toss about with the lovely careless manners founded on extreme confidence. This is a high self-esteem culture. Girls feel beautiful, wheeling their weekend suitcases through the streets of Conil - the closest thing on this coastline to a concrete resort - yelling with excitement. At night the dancing and drinking in the towns this far south goes on late, but there is relatively little brazen drunkenness. A taxi driver in the town of Zahara marvelled to me, a full six years after the event, about a blind-drunk English wedding guest he'd transported to her guesthouse. 'At the age of 45,' he shook his head, more in amazement than disdain. '45!' Pictured: The Royal Andalusian School of Equestian Art; Moorish tiles in Vejer.

Vejer rises from the flat coastal plain beyond the Cape of Trafalgar with the paradisiacal salt-whiteness of a Ladybird-book illustration. Surrounded by medieval walls, it is the jewel of this region, a bright, dream city of churches and palaces and wooden doors giving onto mosaiced interior patios with wafting muslin awnings. Its tiny, tangled and irregular streets follow the ups and ups of a rocky hill. Wandering the close labyrinth of these alleys, past delicate wrought-iron balconies, Vejer feels unlike any other pueblo blanco. Restaurants serve tagines and add mint to their gazpacho. Roof terraces laden with immaculate hammocks drip with just-watered roses. The smell of incense in cafés ('established 1962') promises the hippy trail and Africa, but the potted plants along the scrubbed cobbles look more like 6th-arrondissement Paris.

Vejer might echo with distant civilisations going back 5,000 years to the invasion of the Cretans (bulls are raced through the streets here once a year), but the town is supremely, cleanly elegant. Everything feels amplified, the people stylish and amiably indolent. From the highest point in the city, the view is of richly irrigated fields of tomatoes, pimentos and watermelons, the sound is of cuckoos and honeybees, busying to and from a nest in the wall of El Devino Salvador Church, which still brandishes an ancient Star of David, recalling a time when the area around Plaza Angel was a Jewish quarter.

Sunset in Vejer comes on with an immense yellow ochre, thinning to lilac for an impossibly long time. In Plaza España, under a moon as bright as a streetlamp, Chinese hibiscus reflects off the shiny green 19th-century ceramic frogs dotted about its fountain, and amontillado-swilling couples order saffron-baked lamb at restaurant tables. Long after midnight, in a small domed kiosk, an elderly woman in black crepe smokes and listens to the radio, selling poker cards and lottery tickets for a pittance. And then later still, a cat sniffs the remains of a dried lizard in a side street, relaxed in its moment of feline solitude, eventually distracted by the call of a nightingale.

Casa Viña de Alcántara, Jerez [/b] Just 15 minutes' drive from the city centre, Casa Viña de Alcántara stands in fields of wheat, surrounded by poplars. A peerlessly renovated lodge owned by a wine-growing family, it has just a handful of perfectly chic rooms and a shaded pool. It's close enough to the airport to be your only destination for an absurdly romantic weekend, interrupted by the occasional taxi ride into town for tapas and sherry. (+34 956 393010; www.vinadealcantara.com). Doubles from about £140.

La Vista de Medina, Medina Sidonia [/b] More basic than boutique, La Vista de Medina is still that almost impossible thing: a place to stay with a lovely pool in this steepest of hot, remote hill towns. The view from the terraced restaurant is legendary, and the owners wrap you in blankets if the winds pick up. Medina is a thrillingly authentic town, full of rejas, the protruding boxed windows encased in metal bars that recall young couples' murmured late-night conversations without chaperones. (+34 956 410069; www.lavistademedina.com). Doubles from about £50.

Hotel V, Vejer Hotel V is a charming, smart hideaway in an ancient building at the very top of town, with a hot tub on the roof terrace so high kestrels and buzzards hover only feet away. This hotel is precisely where you want to be: moments from both quiet bars and churches and a busy central square, and yet it's always peaceful. Order the breakfast of mango and tiny local sheep's cheeses. (+34 956 451757; www.hotelv-vejer.com). Doubles from about £125.

Casa La Siesta, Vejer A short drive fromthe city into the lush farmland below, Casa La Siesta is a country house that looks like a Roman villa. Its large rooms give onto a leafy courtyard that leads down to a garden pool. It's also a horse sanctuary, and friendly stallions wander past eating the sunflowers. Lunch and supper cooked by a health-conscious chef are a nice change from the mostly fried southern-Spanish tapas. (+34 699 619430; www.casalasiesta.com). Doubles from about £185.